In recent years, it has become popular to provide musical concerts to large audiences, which audiences will not fit into standard concert hails or theaters because of space limitations. In the case of popular bands or musical performers, such as rock and roll bands or country and western singers, such performances have been provided in large sports arenas, such as baseball, football, or soccer fields, or other spacious outdoor facilities, including beaches or pastures. In order to provide a stage for the set-up of musical instruments and for providing a platform for the performers, such stages had to be constructed on-site from the ground up. Sports facilities, pastures, and beaches which can accommodate the large crowds attending the performances, are not normally equipped with the type of permanent covered stage from which the performers' equipment, including musical instruments, amplified speakers, video screens, lights, pyrotechnics, and other special effects, can be suspended and displayed. Further, because of the sensitivity of much of the equipment, including complex electronic lighting, amplifiers, speakers, video equipment, and the like, to weather conditions, the modern stages must be provided with adequate stable and secure roof coverage. In order to accommodate the complete visual effect of the performance and to allow all aspects of the performance to be viewed from the large audience, the roof must be spaced a substantial distance above the stage platform.
In the past, stage roofs have been constructed with the expenditure of much time and effort using standard building or scaffolding techniques, which to a large extent required extensive bolt tightening or clamping during assembly of the support structure and stage walls. There was a corresponding bolt loosening and clamp loosening during disassembly. Many of the roofs had to be constructed using cranes and workmen atop of the scaffolding or stage walls for long periods of time. Complex construction procedures at the top of the walls were dangerous and time consuming.
In recent years, it has been found that roof assemblies could be more simply and more safely constructed at ground level or at a stage platform level and then raised to above the ground or platform suspended from the top of scaffolding with steel cables. Such construction was less complicated and less time consuming, but nevertheless, necessarily resulted in a less stable roof configuration due to the flexibility of the suspension cables. Excessive tension in the cables, in order to reduce their flexibility, could cause dangerous overloading both of the cables, as well as the stage walls or scaffolding from which the cables were supported.
Many modern live performances often tour from one city to the next to provide the same or similar shows for different audiences at separate locations on such a multi-city or multi-national tour. Each new performance requires that a stage be provided. To the extent that the show relies upon a tower and roof assembly, it is advantageous to have the same tower and roof construction provided at each show for each repeat performance. In order to provide a stable tower and roof system at each location, heavy base blocks are used to form a foundation for the tower and roof assembly at each location. Generally, the heavier the base block, the better for stability purposes; however, each pound of additional weight must be loaded on transport vehicles, transported and unloaded and repositioned between each stage setup between the performances at different locations. In the past, either the base blocks had to be smaller and of lighter weight than most desirable, for safety purposes, or the extra cost for transporting, loading, unloading, handling, positioning and leveling of heavy base blocks had to be incurred between each setup. Also, to keep the size and weight manageable, it was sometimes necessary to provide separate tower pedestals, so be attached to the base blocks. The base blocks, the pedestal and the tower sections were separately of a manageable weight, but additional handling and assembly increased the time and cost of construction at each site.